Don't recursively process values with a toCSS function

stylesToCSS has code to run the toCSS function on a value if it exists,
but createStyle method will try to recursively process the object first.
Don't add px to unitless numbers
Merge pull request #74 from ianobermiller/tocss

Don't recursively process values with a toCSS function
Merge pull request #75 from ianobermiller/unitlessnumber

Don't add px to unitless numbers
Work in progress.
Merge branch 'master' of https://github.com/js-next/react-style into 0.4
Removal of selector duplication.